C2-C8 hydrocarbon measurement and quality control procedures at the Global Atmosphere Watch Observatory Hohenpeissenberg.

A new automated on-line GC-flame ionization detection system for long-term stationary measurements of atmospheric C2-C8 hydrocarbons in the lower ppt range is described. The system is operated at the Global Atmosphere Watch Observatory Hohenpeissenberg (47 degrees 48'N, 11 degrees 01'E) in rural south Germany. Atmospheric mixing ratios of more than 40 different hydrocarbons can be continuously measured in 80 min time intervals. Corresponding detection limits are below 3 ppt, except for propene, butenes and benzene (about 10 ppt). Detailed quality assurance and quality control protocols are described which are applied to routine operation and data analysis. The various error contributions, overall precision, and accuracy for all measured compounds are discussed in detail. Typical ambient air mixing ratios are in the range of a few ppt to a few ppb, and corresponding measurement accuracies are below 10% or 10 ppt. For less than 20% of the analyzed compounds measurement accuracies are worse, mainly because of insufficient peak separation, blank values or reduced reproducibilities. The present system was tested in international intercomparison experiments (NOMHICE, AMOHA). For most of the C2-C8 hydrocarbons analyzed, our results agreed better than +/- 10% (20% NOMHICE phase 5) or +/- 10 ppt with the corresponding reference values.

Medical practice and informatics tools: a vignette.

In this article the authors recreate an improvisational vignette originally presented at the Third Annual Information Connection in Burlington, Vermont, in January 1998. The vignette illustrates various state-of-the-art decision-support systems for clinical care and their promises and problems in real-world medical practice. The characters are Dr. Alex Grant, a rural physician in solo practice; Anna Everett, a patient suffering from chronic headaches; Bob, a hospital librarian; and Sarah, Dr. Grant's nurse. The short play centers on Dr. Grant's attempt to diagnose the cause of Anna's headaches (which he and she believe to be sinus-related) and the roles information technologies--Medline searching, Anna's own Internet searches, the use of MDConsult, which provides Internet access to standard medical texts, journals, etc., and a desktop decision-support tool called Problem Knowledge Couplers--play in this process. The vignette concludes with the realization that while computer technologies can be of great help in medicine "there is still a need for a good doctor to pull it all together."

Networking a need: a cost-effective approach to statewide health information delivery.

VTMEDNET is the health information network for the state of Vermont. In response to a needs assessment of rural health care providers, it supports e-mail, access to knowledge-bases, and the ability to request library services for health care providers across the state, regardless of their location or affiliation. For Fletcher Allen Health Care affiliates, it also supports access to in-patient hospital records. Two thirds of the state's physicians are using the network as well as many other health care providers, and, with minimal cost, it has begun to meet its goal of improving health care delivery to many of Vermont's citizens.